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4 Sheets-Sheet 1 W. J. PEETS GENTERLESS GRINDER orig ihal F ile d June14, 192] Oct. 22, 1929'.

INVIENTOR Wfi I BY ATTORNEY w. J. PEETS Oct. 22, 1929.

CENTERLESS GRINDER Original Filed June 14. 1921 4 sheetsfsheet 2 h2g5?By m I W. J. PEETS CENTERLES S GRINDER Oct. 22, 1929-.

' original Filed June 14, 192i 4 sheets-sheets OR Z2 TTORNEY INVENT WWIm Q M INVENTOR 4 Sheets-Sheet 4 J. PEETS OENTERLESS GRINDER 0riginalFiied June 14. 1921 Oct. 22, 1929.

Reissue-d Get. 22. 129

tilNITED STAES ATENT orrlca WILIBUB J. BEETS, OF ELIZABETH, NEW JERSEY,ASSIGNOR, IBY MESNE ASSIG-NJYIENZIPS, T0 CINCINNATI GRINDERS INGOBPOBATED, 0F CINCINNATI, OHIO, A CORPORATION OF (OHIO Original No.1,599,584, dated September 14, 1926, Serial No. 477,355, filed June 14,1921. Application for reissue filed May 18, 1927. Serial No. 192,456.

i This invention relates to an automatic centerless grinder and has foran object to provide a grinder of the centerless type in which thearticles to be ground are automatically fed to the grinding point from asource of supply and also automatically discharged from the grindingpoint after the grinding operation has been completed. It is also anobject of the invention to provide a machine 0 of this type which willsimultaneously grind two or more spaced bearings on a single articlesuch as a crank-shaft.

With these and other objects in View, the machine, in its preferredform, is provided with one or more sets of peripherally opposed grindingand work-rotating and governing or controlling wheels. The grindingwheel or wheels is or are mounted on a slide which in operation may becontinuously reciprocated ina direction longitudinally of the axes ofthe wheels which are rotated at a relatively high speed.

The work rotating or governing wheel or wheels is or are mounted on aseparate slide which is automatically fed toward and from the peripheryof the grinding wheel to allow for the insertion and removal of the workand also operates a work-feeding means in proper timing relationtherewith. Referring to the accompanying drawings, Fig. 1 is a frontelevation of my grinder. Fig. 2 is a transverse section substantially onthe line 22 of Figs. 1 and 4. Fig. 3 is a transverse sectionsubstantially on the line 3-3 of Figs. 1 and 4. Fig. 4 is a top planview upon a reduced scale. Fig. 5 is a detail plan view of'the cam-platefor shifting the governing wheel. Fig. 6 is a detail end View of awork-support. Fig. 7 is a side elevation thereof. Fig. 8 is a detail ofthe means for reciprocating the grinding wheel. Fig. 9 is aview showingthe development of; the cam groove in the cam-cylinderi'92, and Flg. 10is a detail view of a portion of the work feedwith a slideway comprisingan inverted V 2 and a plain bearing rib 3upon which is mount- 6d a slide4 which carries one or more gr ndriphery of these wheels.

in the frame 1.

belt 9 tight at all times. I from Fig. 3 that the belt 9 passes upwardlying wheels 5. In the present instance two grinding wheels are shown.These grinding wheels are what are termed peripheral grinders in thatthe grinding surface is on the pe- Each wheel is sup ported by a shaft5' which is mounted to rotate in spaced bearings 6 and 7 mounted uponthe slide 4. The grinder-shaft between the bearings is provided with apulley 8 which is driven by means of a belt 9 passing to a drivmg pulley10 mounted upon the main powershaft 11 which rotates in'bearings12 and13 The shaft 11 is located below the slide upon which the grindingwheels are mounted so that it and the driving pulleys are located withinthe frame and are completely enclosed thereby.

Fulcrumed upon the shaft 11 is a frame 14 having a free arm at the endof which is rot'atably mounted an idler-pulley 15 adapted to bearagainst the belt 9 and this frame 14 also has an arm 16 to which isattached one end of a spring 17 ,the other end of this spring 17 tendsto turn the frame 14 on the shaft 11 and through the idler pulley 15maintains the It will be noted from the pulley 10 through a convenientopening 19 formed in the upper wall of the frame 1.

The slideway 2-3 extends longitudinally of the frame 1 and substantiallyparallel with the axes of the. grinding wheels, the slide 4 being formedwith inverted V and plain surfaces to slide upon the surfaces 2 and-3.The slide 4 is also formed on its upper surfaces with slideway 20extending transversely of the slideway 2-3, and mounted to slide in eachof the slideways is a second slide 22 which carries the bearings 6 and 7for the grinding wheel shaft 5, there being a slide for each .wheel. Theouter end of this slide is provided with a bearing 23 in which ismounted ar'otatablescrew 24 having screwthreaded engagement with a lug.25 on the slide 4 and is provided at its outer end with a gear. 26. Asecond gear 27 meshes with the gear and is mounted upon the inclinedshaft 28, this shaft being rotatably mounted at one end in the bearing29 immediately above the bearing 23 and at the other end in a bearing 30above the grinding wheel shaft. The shaft 28 has mounted thereonadjacent the bearing 30 a worm-gear 31 which meshes with a Worm 32mounted upon a short shaft 33 provided with a graduated 'disk 34 havinga handle 35 for convenient manipulation. It will be evident that byrotation of the disk 34 the shaft 28 and' screw 24 will be rotated andthe slides 22 may be adjusted back and forth on the slide 4 as desired.The shaft 33 carrying the worm 32 and the disk 34 is mounted in anadjustable bearing 36, this bearing being fulcrumed on a portion 37 ofthe frame integral with the bearing 30 and is rovided with a curved slot38 through which a bolt 39 screwed into the support 37 extends. Byloosening the bolt 39 the bearing 36 may be turned about its fulcrum 36to move the worm 32 out of mesh with the worm-wheel 31 and a crankmaythen be applied to the square end 40 of the shaft 28 allowing rapidrotation of the screw 24 to give a rapid rough adjustment to the slide22 supporting the grinding wheel.

The grinding wheels are mounted upon the slide 4 so that they may bereciprocated continuously longitudinally of their axes during the normalgrinding operation. The

amount of this reciprocation is small, in

the present instance, about three-sixteenths of an inch beingsuflicient. The amount of reciprocation, however, depends upon the typeof work to be performed. In some classes of work no reciprocation isgiven to the grinding wheels. The reciprocatory movement is imparted tothe slide 4 by means of a crank which is rotated from themainpower-shaft 11. As shown more clearly in Fig. 2 a short shaft 41 ismounted in the frame 1 above the main power-shaft 11 and these twoshafts are provided with 'in termeshing spur-gears 42 and 43respectively. The shaft 41 is also provided with a worm 44 meshing witha wormwheel 45 on a vertical shaft 46, which latter shaft at its upperend carries a collar 47 having a transverse groove 48 in which isadjustably mounted a block 49 (Fig. 8). The collar 47 is provided withadjusting screws 50 and 51 extending through the walls thereof fromopposite ends of the groove 48 and bear upon the ends of the block 49.By adjusting these screws the block 49 which carries a pin 52 may beadjusted to locate said pin eccentrically of the shaft 46 and the amountof this eccentricity will determine the amount of throw of the pin 52 asthe shaft rotates In the presentconstruction the block49 may be adjustedto give a reciprocation varying from zero to one quarter of an inch. Thepin 52 extends into an opening in the block 53 mounted within a channel"54 formed in a downwardly extending boss 55 on the under side of theslide 4. The channel 54 extends in a direction transversely of theslideway 23. It will therefore beseen that as the shaft 46 rotates andwith it the eccentrically" located pin 52, the slide 4 will bereciprocated longitudinally of the slideway 2-3 and in a directionlongitudinally of the axes of the grinding wheels 5, but thatnotransverse movement will be imparted to this slide because the block 53has free sliding movement in the transverse channel 54. The gearing 44,45 is a reducing gearing so that the shaft which is mounted for slidingmovement a .slide 58. This slide is provided on its upper side 'withinclined Walls 59 adapted to form a sliding connection with a V groovein the underside of another slide 60. It will be noted that theslideways 57 and 59 extend in a direction transverse to the slideway2-3. The slide 60 is provided with upwardly extending bearing supports61 which carry bearings 62, 63 for a shaft 64 mounted to rotate therein,the axis of the shaft extending substantially parallel to the axes ofgrinding wheels 5. The shaft 64 carries opposite each grinding wheel agoverning wheel 65 which is rotated at a relatively low speed by meansof mechanism which will now be described.

Secured to the wall 56 are bearing brackets 66 supporting a'short shaft67 carrying pulleys 68 and 69., The pulley 68 carries a belt 70 whichbeltalso passes over a pulley on the main-shaft 11. A second belt 71connects the pulley 69 with a pulley 72 on a short shaft 73 mounted inbearings 74 carried by the slide 60. An idler pulley 69' mounted onaframe 69 fulcrumed on shaft 67, is pressed against belt 71 bya spring 69secured at opposite ends to the frames 69 and 1, and keeps the belttight in a well known manner. On the opposite side of the bearing 74 theshaft 73 is provided with a bevel gear 75 meshing with a second bevelgear 76 on the shaft 77 extending at right angles to the axis of theshaft 73. this shaft-being mounted in a frame 78 adj ustably secured onthe slide 60-. This latter shaft 77 is provided with a worm 79 meshingwith a worm-Wheel 80 upon the shaft 64 carrying the work-governingwheels 65. This train of driving mechanism from the shaft 11 rotates thegoverning Wheels 65 in a direcand 3 at a relatively low rate of speed.

Mounted upon an upstanding portion 81 of the frame 1 by means ofsuitable supporting means is a work-rest or support 82, there being oneof these supports between each pair of grinding and governing wheels.The S1! P tion counter-clockwise as viewed in Figs. 2.

porting means for this work-support comprises a bracket 82' beingsecured upon the block 83 by means of bolts 84, the heads of whichextend into T-slots 83 formed upon the upper end of the block 83, theother end of the bolt passing through an outstanding lug 85 upon thebracket 82' (Figs. 6 and 7). Above and spaced from the lugs 85 thebracket 82 is provided with other outstanding portions 86 each providedwith a verticalhole through which extends the vertical leg 87 of anL-shaped bolt, the, horizontal leg 88 of this bolt being adapted toenter a hole or socket drilled in the end of the work-rest 82, as shownin Figs. 6 and 7, the lower end of the vertical leg 87 of the L-shapedbolt being provided with a nut 88 by means of which the work-rest 82 maybe clamped in the V-shaped groove 89 formed in the top surface of thebracket 82. In operation the work represented in dotted lines at 90 inFigs.

6 and 7 rests upon the top of this tubular support 82 and is adapted tofreely rotate thereon during the grinding operation. 7

As during the grinding operation the work 90 is not fed across thesurface of the grindingwheel it is necessary in bringing the work togrinding position and discharging it therefrom that one of the wheels bemoved away from the other. Either wheel may be moved to allow for theinsertion and removal of the work, but practically it is easier and moreconvenient to move the governing wheels 65 operation is completed, thegrinding wheels rest.

with the work-rest, and the governing wheel or wheels be separated asuificient distance to allow the work to drop from the rest between itand the suffacespf the governing wheels into the trough 91. It, ispreferable to obtain this separation by retracting the governing wheelor wheels away from the work- After'the finished work has dropped 1n thetrough the wheels 65 must be ad vance toward the work-support asuflicient distance to prevent the unfinished work passing between itand the work-rest when this piece of unfinished work is dropped onto'the rest. The governing wheels 65 are then advanced to press the workagainst the grinding wheels and are given a slow'feeding movement duringthe grinding operation. These retracting and advancing movements areimparted to the slide 60 carrying the governing wheels 65 through twocam elements 92 and 93 operating in series.

Secured to and extending downwardly from the bottom wall of the slide 58is a block 94 provided with a downwardly extending lug 95 and ananti-friction roller 96 mounted on a stud 97 secured to said block 94.

The sliding cam element 93 cooperates with the lug 95 and theanti-friction roller 96 to reciprocate the slide 58 in certain timingrelation with the grinding operation. The sliding cam element 93 isprovided on the upper surface thereof with upwardly extending lugs 98and 99 which coact with the antifriction roller 96. The cam element 93is also provided with lugs 100 and 101 in which is adjustably supportedthe ends of an adjustable cam ,element 102 as more clearly shown in Fig.5. The lug 98 is provided with two straight surfaces 103 and 104 betweenwhich is an inclined surface 105 and opposed to these surfaces the lug99 is provided with an inclined surface 106 substantially parallel tothe surface 105 and straight surfaces 107 and 108 parallel to thesurface 104 but between the two with a substantially V-shaped projection109. The cam element 102 is located on the opposite side of the lug 109and is provided with a straight but inclined cam surface 110 whichcoacts with the lug 95. The cam element 102 is provided on each end witha threaded stud 111' and 112 having nuts by which the cam element may bead justed longitudinally to vary the effect of the camsurface 110 uponthe lug 95. The cam element or plate 93 is slidably mounted in aguideway 113 in the frame 1 and is guided therein by means ofguide-plates 114. The cam-plate 93 is provided on its upper surface withan anti-friction roller 115 mounted on. a stud 116 secured in the plate,the stud and the roller projecting downwardly through a convenient slot117 formed in the frame. The anti-friction roller 115 tracts.

with a cam-groove 118 in the cylindrical surface of the cam element 92.This groove is shaped vto reciprocate the plate 93 in a directionlongitudinally of the axis of the grinding and governing wheels. Byvarying the shape of this slot 118 the movements of the plate 93 ofcourse may be varied as desired to advance and retract the governingwheels 65 in different timing relations. In the present embodiment thisgroove is shaped substantially as shown in Fig. 9 in which passage ofroller 115 through the inclined portion it moves plate 93 while thegoverning wheels 65 are being retracted from the grinding-wheels 5 toallow discharge of the work, portion 5 brings the wheels through theirfirst advancing movement to loading position, 0 is the loading positionand d is for the 'grindingoperation The camele ment 92 is mounted'on ashaft 119 provided with a worm-wheel 120 which meshes with a worm 121mounted on the shaft 122 extending at right angles to the shaft ll inthe lower part of the frame 1. A second shaft 123 parallel with theshaft 122 is provided and it has a bevel gear 124 meshing with a bevelgear 125 on the main-shaft 11. The other end of the shaft 123 isprovided with a spur-gear 126 meshing with the second spurgear 127 onthe shaft 122. Betweenthe spurgear 127 and the worm 121 is provided aclutch 128 of any usual construction with a lever 129 extending beyondthe frame 1 so that driving connection between the spurgear 127 and theworm 121'may be disconnected at any time to stop the automatic advancingand retracting of the regulating wheels 65.

As it is desirable that the regulating wheels 65 be given a rapidretracting movement from the work-rest after the grinding operation iscompletedto allow the work to drop from the rest into the trough 91,this movement is imparted to the supporting slide 58 by the inclinedsurface 105 reacting against the anti-friction roller 96 as thecam-plate 93 is moved to the right as shown in Fig. 5, the anti-frictionroller 96 being then in the dotted line position shown in this figure.The governing wheels 65 are advanced to the grinding position in twostages both of which are comparatively rapid movements. The firststage-is caused by the action of inclined surface 106 on theanti-friction roller 96 as it is moved to the left as shown in Fig. 5.This advances the governing wheels 65 sufliciently close to thework-rest to prevent work dropping from the rest into the chute 91, butit is not sufficiently advanced to press the work against the grindingWheel. The governing wheels are retained in this position while theroller 96 advances along the dwell 107 and during this dwell a piece ofunfinished work is dropped on to the work-rest by automatic means whichwill later be described. After this piece of work has been dropped ontothe rest the incline 109' on the projection 109 advances the governingwheel to grinding position to press the piece of work against thesurface of the grinding wheel 5. During the grinding operation, however,there must be a very gradual feeding movement imparted to the governingwheels 65 and this is attained by the action of the slightly inclinedcam-surface 110 against the projecting lug 95. After the lug 95 haspassed throughout the entire length of the inclined cam-surface 110 thegrinding operation is continued for a short time until equilibrium isobtained, that is, until the work has been sufficiently reduced thatthere is practically no pressing of the work by the wheel 65 against thegrinding wheel. This action is allowed by means of a dwell which may bean extension of the surface 110 or may be in the cam-groove 118.

As pointed out above the slide supporting the governing wheel or wheelsis slidably mounted upon the slide 58, but this mounting is wholly forthe purpose of adjustment. The slide 58 is provided with an upstandinglug 130 having threaded engagement with a screw 131 mounted in a bearing132 on the slide 60. -The outer end of this screw 131 is provided with aworm-wheel 133 meshing with a worm 134 secured on a short shaft 135rotatably mounted in a bearing 136, the other end of this shaft beingprovided with a graduated disk 137 having a handle 138 by means of whichit may be rotated to rotate the screw 131 to give five adjustments tothe governing wheels 65. The bearing 136 is pivotally mounted on theslide 60 in the same manner as is the bearing 36 mounted on its support37, that is, so that by loosening a nut 139 on a bolt extending magaz1nehas a short vertical guide passage 142 which is adapted to contain oneor more pieces of work and through the lower end of which a plunger rod143 passes. Below the plunger rod is a supporting surface hafing a bulge144 between the lower end of the chute 142 and a second chute 145 forguiding the work to the top of the work-rest. The second chute 145 isspaced a short distance from the lower end of the chute 142 so that thework will not drop directly from the chute 142 to the chute 145 but mustbe transferred the short distance between them by means of the plunger143 which plunger is attached in any suitable manner, in the presentinstance, by a set-screw 146 to an upstanding support 147 mounted on andmovable with the support for the governing wheels 65. .In the presentinstance, as there are two sets of opposed grinding and work-rotating orgoverning wheels, there are two plungers 143, 7

one adjacent each set of wheels, and these plungers contact with the twoopposite ends of a piece of work 148, so as to give a more reliableoperation. It will be obvious that, when the governing wheels 65 areretracted under the action of the cam 105 to allow the work to drop fromthe work-rest, the plunger 143 will also be retracted and allow thepiece of work to drop into the recess 149 at its lower end, the bulge144 preventing this work from passing into the chute 145. When, however,the governing wheels 65 are advanced under the action of the cam 106,the plungers 143 push the work over the bulges 144 into A the chute 145so that the work drops onto as described above.

the rest. The work drops while the governing wheel 65 is not beingadvanced or is being advanced at a retarded rate of speed, that is,while the anti-friction roller 96 is on the dwell 107. It is notnecessary thatthe advancing movement of the wheels be stopped a whilethe work is dropped onto the work-rest, but sufiicient time should beallowed for the work to reach the rest before the governing wheels areadvanced to grinding position. This time allowance may be obtainedeither by stopping the advance movement of the governing wheels or bymerely retarding it or advancing them at a reduced speed for a shorttime. After the work has been dropped the cam 109' advances thegoverning wheel to press the work against the grinding wheel In order toproperly guide the work to the work-rest and to prevent its coming incontact with the grinding wheel before-it has reached the rest and thegoverning wheel 65 is advanced to press it against the grinding surfaceas desired, the inner wall 150 of the chute 145 isextended downwardly asshown at 151 close to the surface of the grinding wheel and nearly downto the work-rest. This arrangement effectively keeps the work fromcoming in contact with the grinding wheel 5 until the work has beenplaced in proper grinding position.

As the grinding wheels in operation necessarily wear and under continuedoperation I become more or less untrue they must be trued up in order toproduce accurate work. This operation may be conveniently performed bymeans of a t-ruing tool mounted upon the top of the guard 152 extendingover the grinding wheel In the present construct'on, mounted on a flatsurface of this guard is an upwardly extending bracket 153 provided witha vertical guideway 154 in which is mounted a slide 155. This slide isprovided with a horizontal guideway 156 in which is mounted a secondslide 157, the second slide carrying the tool 158 provided with adiamond point 159. The slide 155 may be in two sections, one of whichispivoted to the other by means of a stud 160 and is provided at its upperend with a curved slot 161 through which extends a bolt 162, the centerof curvative of the slot being the center of the stud 160. By looseningthe nut on the bolt 162 the outer section of the slide 155 may be givenslight angular adjustment to taper the surface of the grinding wheel orto place the tool so as to make the surface cylindrical as desiredduring the finishing operation as will be obvious,the tool being movedover or across the surface of the wheel'by means of a screw 163 providedwith a hand-wheel 164 having screw-threaded engagement with the slide157. The vertical position of the tool may be determined by means of asimilar screw 165 having a graduated hand-wheel disk 166 havingscrew-threaded engagement with the vertically movable slide 155 in amanner well known.

In dressing or truing the surfaces of the governing wheel each 'wheelshould be speeded up and this operation is obtained through a secondshort shaft and suitable gears mounted in the bracket 78. A stud 167 issecured in the bracket 78 with its axis parallel with the shaft 77 andmounted upon this stud is a spur-gear 168 adapted to mesh with aspur-gear 169 on the shaft 77. Integral with or secured to the spur-gear168 is a bevel-gear 170 which meshes with a second bevel-gear 171 gearedto a short shaft 17 2 also mounted in the bracket 78 and which isprovided with a spiral gear 173. Mounted upon the supporting shaft 64for the governing wheel beyond the worm 79 and worm-wheel 80 is a secondspiral gear 174. The bracket 78 is provided with a curved slot 175, anda bolt 176, secured to the frame, extends through this slot and isprovided on its end with a nut 177. By loosening the nut 177 thespiral-gear 173 into'mesh with the spiralgear 174. The gears are soproportioned that this arrangement will increase the speed of thegoverning wheels 65 to give the proper surface speed for the truingoperation. After the truing operation ;is completed the bracket'78 isswung in the opposite direction about the shaft 73, removing the gear173 from in mesh with the gear 174 and restoring the worm 79 into meshwith the gear 80 which is the normal driving relation for the grindingoperation.

The t-ruing tool 184 having a diamond point is mounted in a holder 185on a slide 186 mounted on a second slide 187 the two slides beingmounted on V guides to slide in directions at right angles to eachot-her, slide 186 being movable toward and from the governing wheeltransverse the axis thereof by means of a screw operated by hand-wheel188, and slide 187 'being movable in a direction parallel with the axisof wheel 76 by a screw and hand-wheel 189 to move the tool In the presnormal grindingwheel operation. A receptacle 180 is provided for emerycharged water and a pump driven in any suitable manner from thepower-shaft 11 or any other suitable source of power pumps this waterthrough a system of iping 181 to discharge nozzles 182, located a jacentthe surface of the grinding wheel 5 above the grinding point so thatthis water is discharged onto the surface of the grinding wheel and theWork during normal grinding operation, the water passing downwardly intothe chutes and other hollow spaces within the frame and is drained backinto the receptacle or tank 180 to be used over again, there being acontinuous circulation of this water.

In operation the grinding wheel 5 is rapidly rotated in the direction ofthe arrow, Figs. 2 and 3, the surface contacting with the work movingdownwardly toward the top of the work-rest. The governing wheels 65 areslowly rotated in the same direction as also shown by the arrows, thesurface contacting with the work moving upwardly away from the top ofthe work-rest. It will be seen that when this wheel presses the workagainst the surface of the grinding wheel, the work is rotated slowly ina clockwise direction as viewed in Figs. 2 and 3, and the surfacethereof is ground by the action of the grinding wheel 5. Assuming thatthe operation of grinding a piece of work has been completed, under theaction of the cam surface 105 the governing wheels 65 preferably arerapidly retracted away from the work-rest a suifi- -cient distance toallow the work to drop from this rest into the chute 91 from which itpasses into a suitable receptacle. To obviate all possibility of thework remaining on the rest when the Wheels 65 are retracted a spring 183is secured upon the support for the workrest as shown in Fig. 2 andrests against the side of the work ad]acent the grinding wheel andnormally tends to press the work against the surface of the governingwheels 65. It will therefore be obvious that when the governin wheels 65are retracted, this spring will fhrce the work to the left as shown inFig. 2, away from the surface of the grinding wheel so that it willnecessarily fall into the chute 91. The governing wheels 65 are nowadvanced under the action of the cam 106 to a position spaced somewhatfrom the work-rest but not suflicient to allow the work to pass betweenit and the work-rest. This advance movement of the wheels 65 alsoadvances the plungers 143 which transfer a piece of work from the bottomof the chute 142 into the chute 145 Where it is guided to the top of thework-rest. The governing wheels 65 are now advanced under the action ofthe projection 109 to normal grinding position to press the work againstthe grinding wheels 5 and the reaction thereof will give sufiicient gripfor the wheels 65 on the work to rotate it as will be obvious. Duringthis rinding operation the wheels 65 are slowly a vanced toward thegrinding wheels an amount equal to the amount of stock which is to beremoved'from the work,-after which the grinding operation is continued ashort time without any feeding movement toward the grinding wheel beingimparted to the governing Wheels 65. The work is now finished and thegoverning wheels 65 are again retracted to allow removal of the workfrom the work-rest. During the grinding operation the slide 4 upon whichthe grinding wheels 5 are mounted is preferably continuouslyreciprocated in a direction longitudinally of the axis of these wheelsby means of the gearing 43, 42, 44, 45 and the crank 52 so as to give auniform rinding throughout the surface to be ground and to compensatefor any inequalities in the surface of the grinding wheel such as occurbecause of unequal wear due to non-uniform hardness of differentportions of the rinding wheel.

In the present construction as will be noted there are two sets ofgrinding and regulating wheels spaced from each other longitudinally oftheir axes of rotation. By this arrangement two independent and spacedbearing surfaces may be simultaneously ground upon a single element suchas a crankshaft 148. It is to be distinctly understood, however, thatthis invention is not limited to two sets of grinding and regulatingwheels as more mag be employed and the same principle may e employedwith a single set of grinding and regulating wheels to grind one bearingsurface at a time, such as the shanks of headed bolts and similararticles.

It will be seen from the foregoing that the machine is entirelyautomatic, the work being automatically discharged from and fed to thegrinding position as the governing wheels 65 are automatically retractedand advanced under the operation of the cams.

Having thus set forth the nature of the invention, what i claim hereinis:

1. A centerless grinder comprising low and high speed wheels adapted tosimultaneously press in opposite directions upon a workpiece, awork-rest for holding work in operative relation to said wheelspermitting the work-piece to rotate and adjust itself to the opposedpressures of said wheels, automatic means for feeding a work-piece togrinding posit-ion on said work-rest, and automatic means for relativelyapproaching said wheels to grind the work-piece to size and forrelatively separating them when the grinding operation is completed toallow the Workpiece to fall from its support through the space providedby separation of said wheels.

IOIK

2. A centerless grinder comprising low and till proaching said wheels togrind the workpiece to size and for relatively separating them when thegrinding operation is completed to allow the work-piece to fall from itssupport, said automatic feeding means being timed to feed a work-pieceto grinding position after said wheels have been relatively approachedpart way from Work-discharging position to grinding position.

3. A centerless grinder comprising low and high speed wheels adapted tosimultaneously press in opposite directions upon a rotatable work-piece,a work-rest permitting the workpiece to rotate and adjust itself to theopposed pressures of said Wheels, automatic means for.

imparting a two-stage approaching movement to said wheels to relativelyplace them first in work-receiving position and second in grindingposition, said means being constructed to relatively separate saidwheels when the grinding operation is completed, and means for feeding awork-piece to the work-rest after the wheels have been relativelyapproached to work-receiving position.

4. A centerless grinder comprising a peripheral grinding wheel and awork-governing wheel having its periphery opposed to thatof the grindingwheel, means for holding work in operative relation to said Wheels andpermitting the work to adjust itself to the simultaneous opposedpressures of said wheels, means for rotating said grinding wheel atgrinding speed and said governing wheel at a low speed to control therotation of the work, the portion of the work surface contacted by thegoverning wheel moving in the same direction as the operative surface ofthe governing wheel and the grinding wheel being rotated so that itsoperative surface moves past, and in the same direction as, the portionof the work surface being ground by said grinding wheel, and means for"continuously reciprocating said grinding wheel longitudinally of itsaxis during normal operation.

5. A centerless grinder comprising peripherally opposed grinding andwork-governing wheels, means for rotating said grinding wheel at agrinding speed and said governing wheel at a low speed to control therotation of the work, the portion of the work surface contacted by thegoverning wheel moving in the same direction asthe operative surface ofthe governing wheel and the grinding wheel being rotated so that itsoperative sur face moves past, and in the same direction as, the portionof the work surface being ground by said grinding wheel, a work-rest forholding work in operative relation to the peripheries of the saidwheels, automatic means for advancing one of the wheels toward and fromthe other wheel to press the work against the grinding wheel and allowremoval of the work from grinding position,

and means for continuously reciprocating the grinding wheellongitudinally of its axis durof the governing wheel and. the grindingwheel being rotated so that its operative surface moves past, and in thesame direction as, the portion of 'the work surface being ground by saidgrinding wheel, a support for holding work in operative relation to thewheels, means for advancing the governing wheel to bring the work intocontact with the grinding wheel and to retract said governing wheel toallow discharge of the work from grinding position, and automatic meansfor continuously reciprocating the grinding wheel longitudinallyof itsaxis during the grinding operation. I

7. A centerless grinder comprising peripherally opposed grinding andgoverning wheels adapted for simultaneous engagement with the work,means for rotating said grinding wheel at a grinding speed and saidgoverning wheel at a low speed to control the rotation of the work, theportion of the work surface contacted by the governing wheel moving inthe same direction as the operativesurface of the governing wheel andthe grinding wheel being rotated so that its operative surface movespast, and in the same direction as, the portion of the work surfacebeing ground by said grinding wheel, a work-rest for holding work inoperative relation. to said wheelsand permitting the work to accommodateitself to the simultaneous opposed pressures of said wheels, a supplymagazine or hopper for holding the work to be operated upon, meansforcausing relative movement between said wheels in a direction transverseto their axes to allow for insertion and discharge of the work, andmeans operable by the relative movement be tween said wheels fortransferring a piece of work from the magazine or hopper to the grindingposition, a

8. A centerless grinder comprising opposed grinding and governingwheels, a work-rest between said wheels, a supply magazine or hopperadapted to hold the work to be operated upon and positioned above saidwork-rest, means for relatively approaching the governing wheel and therinding wheel to press upon a piece of work in grinding positiontherebetween, means for relatively separating said wheels to allow thedischarge of the work from grinding position, and means governed by therelative approaching movement of said wheels to cause a piece of work tobe dropped from said magazine or hopper onto said work-rest.

9. A cehterless grinder comprising opposed grinding and governingwheels, a work-rest between said wheels,y a supply magazine or hopperadapted to hold the work to be operated upon and positioned above saidWork-rest, automatic means for relatively separating the governing wheeland the grinding wheel to allow discharge of the finished work fromgrinding position, automatic means for relatively approaching thegoverning wheel and the grinding wheel in two steps, the first stepbeing a movement insufficient to bring the work into contact with thegrinding wheel, means governed by the relative approach of said wheelsto cause a piece of work to drop from the magazine or hopper to thework-rest at the completion of said first step, said relativeapproaching means being adapted to subsequently further relatively movesaid wheels to bring the work to grinding position.

10. A centerless grinding comprising opposed grinding and governingwheels, means for rotating said grinding wheel at a grinding speed andsaid governing wheel at a low speed to govern the rotation of the work,the portion of the work surface contacted by the governing wheel movingin the same direction as the operative surface of the governing wheeland the grinding wheel being rotated so that its operative surface movespast, and in the same direction as, the portion of the work siirfacebeing ground by said grinding wheel, a work-rest for holding work inoperative relation to the wheels, automatic means for retracting thegoverning wheel from the grinding wheel at the completion of a grindingoperation to allow discharge of the work, automatic means for advancingthe governing wheel toward the grinding wheel in two stages with a dwellor retarded movement between them, and means governed by the advancingmovement of said wheel for causing the work to be fed onto the restduring said dwell or retarded movement.

11. A centerless grinder, comprising opposed grinding and governingwheels, mean-s for rotating said grinding wheel at a grinding speed andsaid governing wheel at a low speed to govern the rotation of the work,the portion of the work surface contacted by the governing wheel movingin the same direction as the operative surface of the governing wheeland the grinding wheel being rotated so that its operative surface movespast, and in the same direction as, the portion of the work surfacebeing ground by said grinding wheel, a work-rest forholding work inoperative relation to the wheels, means for retracting the governingwheel from and advancing it toward the grinding wheel to allow fordischarge of work from and placing work on the rest, and yielding meansadapted to force the work from the rest as the governing wheel perspaced above the rest, and spaced guides forming a substantiallyvertical chute to guide the work from themagazine or hopper to the rest,the walls of the chute being arranged to prevent contact of the Workwith the grinding wheel as it passes to said rest.

13. A centerless grinder comprising opposed spaced grinding andgoverning wheels, means for rotating said wheels, a work-rest betweenthe wheels, a work-magazine or hopper spliced above the rest, and spacedguides forming a chute to guide the work from the magazine or hopper tothe rest, means for retracting and advancing the governing wheelrelatively to the grinding wheel to allow for the discharge and feedingof the work and to bring the work to grinding position, and meansgoverned by the advancing movement of said wheel to transfer a piece ofwork from the magazine or hopper to said chute.

14. A centerless grinder comprising a plurality-of sets of peripherallyopposed grind-- ing and governing wheels, the wheels of each setrotating in the same direction at different speeds, the sets beingspacedfrom each other longitudinally of the axes of, the wheels so as tosimultaneously grind to finished size a plurality of alined bearings ona single element,

means for rotating the grinding and governing wheels, means forrelatively moving said wheels transversely of their axes, and a workrestbetween the wheels of each set.

15. 'A centerless grinder comprising a plurality of sets of peripherallyopposed grinding and governing wheels, the sets being spaced from eachother longitudinally of the axes of the wheels so as to simultaneouslygrind a plurality of alined hearings on a single element, means forcontinuously reciprocating said grinding wheels longitudinally of theiraxes during the grinding operation, and means for simultaneouslyretracting and advancing said governing wheels relatively to thegrinding wheels to allow for the r- I moval and insertion of the workand to bring the work to grinding position.

16. A centerless grinder comprising a plurality of sets of peripherallyopposed grinding and governing wheels, the sets being spaced from eachother longitudinally of the axes of the wheels so as to simultaneouslygrind a plurality of alined bearings on a single,element, means forsimultaneously retracting and wheels relatively to the grinding wheelsto allow for removal and insertion of the work and bring the work togrinding position, a

work-rest between the wheels of each set, a

advancing said governing workmagazine above the work-rests, awork- 1vancing movement of the governing wheel to transfer work from themagazine to said chute.

17 A centerless grinder comprising a fram, a movable slide mounted insaid frame, bearings on said slide, a peripheral grinding wheel mountedto rotate in said bearings, a main power-shaft, operative meansconnecting said shaft and slide whereby the slide and grinding wheel arecontinuously reciprocated longitudinally of the axis of the wheel duringnormal operation, a second slide mounted on said frame and adapted to beshifted in v a direction transverse to the axis of the grind-- ingwheel, a governing wheel mounted on said second slide, means forrotating said wheel, a work-rest for holding work in operative relationto the two wheels, and means connecting said second slide and saidmainshaft, to retract and advance said governing Wheel with respect tothe grinding wheel in certain timed relation to the grinding oper ation.I i g 18. A centerless grinder comprising a frame, a pair of slidesmounted on said frame and adapted to be shifted in directionssubstantially at right angles to each other, a

grinding wheel mounted on one of said slides, a governing wheel mountedon the other slide with its periphery opposed to that of the grindingwheel, means for rotating said wheels,.a power-shaft, and operativeconnections between the slides and the shaft whereby the slides areautomatically shifted.

19. A centerless grinder comprising a frame provided with a plurality ofslideways, slides mounted on said slideways, opposed grinding andgoverning wheels mounted on said slides so that they may be moved towardand from each other, a work-rest for holding work inoperative relationto said wheels permitting the work to adjust itself to the simultaneousopposed pressures of said wheels, a main power-shaft mounted in bearingsinsaid frame below said wheels, and means for driving said wheels fromsaid shaft.

20. A centerless grinder comprising a frame, agrinding wheel mounted onsaid frame, means for rotating said wheel, a slide movably mounted onsaid frame, a governing wheel mounted on said slide, means for rotatingsaid governing wheel, a work-support for holding work in operativerelation to said wheels permitting the work to adjust itself to thesimultaneous opposed pressures ofsaid wheels, means for moving the saidslide with the governing Wheel toward and from the grinding wheel incertain timed re:

, lation with the grinding operation, said means comprising a movablecam-plate having cam-surfaces, means on the slide cooperating with saidcam-surfaces, a cam-disk proously press in opposite vided with acam-groove, means on the camplate coacting with said groove, and meansfor rotating the cam-disk.

21. A centerless grinder comprising opposed grinding and governingwheels, 9. work-support for holding work in operative relation to saidwheels, and automatic means for retractingand advancing said governingwheel relatively to the grinding wheel to allow for discharge andinsertion of work between said wheels, said means comprising two cammeans operating in series, and means for operating said cam means.

22. A centerless grinder comprising opposed grinding andgoverningwheels, means for supporting one of the wheels so that it maybe moved toward and'from the other wheel, a'work-rest for holding workin operative relation to the wheels adapted to 'support the work duringthe grinding operation, and automatic means for advancing the movablewheel to press the work against the other wheel and for retracting saidwheel to allow of the discharge (if the work after the grindingoperation is completed;

23. A centerless grinder comprising low and high speed wheels ada ted tosimultaneirections" upon a work-piece, a work-support between saidwheels permitting the work-piece to adjust. itself to the opposedpressures of said wheels, and automatic means for relatively approach-.ing said wheels to grind the work-piece to size and for relativelyseparating them sufii ciently to permit the work-piece to fallvbygravity from said work-support through the space between the latter andone of the wheels. 24. In apparatus of the character described, incombination, a grinding throat adapted for simultaneous grinding androtating action upon work of round section and comprising three means,one of which means is in the form of a grinding wheel adapted to berotated at a relatively high speed, another of said means being in theform of aregulating wheel adapted to be rotated at a relatively lowspeed to control the rotation of the work, the portion of the worksurface contacted by the regulating wheel moving in the same directionas the operative surface of the regulating wheel andthe grinding wheelbeing rotated so that its operative surface moves past, and in the samedirection as, the portion of the work surfacebeing ground by saidgrinding wheel, and the third of which means includes a member forholding work of round section in operative relation to said two wheels;and power driven means for moving one of said means to change therelation of the grinding throat to the work.

25. In apparatus of the character described, in combination, a grindingthroat adapted for simultaneous grinding and rotating action upon workof round section and comprising three means, one of which means is ofthe work surface being ground by said grinding wheel, and the third ofwhich means lncludes a member for holding Work of round section inoperative relation to said vtwo wheels; means for moving one of saidmeans to change the relation of the grinding throat to the Work and torelease the latter from the grip of the wheels; and means acting intimed relation to the actuation of said last mentioned means forremoving a work-piece from the grinding throat.

26. In apparatus of the character described, in combination, a grindingthroat adapted for simultaneous grinding and rotating action upon workof round section and comprising three means, one of which means is inthe form of a grinding w-heel adapted to be "rotated at a relativelyhigh speed, another of said means being in the form of a regulatingwheel adapted to be rotated at a relatively low speed to control therotation of the work, the portion of the work surface contacted by theregulating wheel moving in the same direction as the operative surfaceof the regulat-' ing wheel and the grinding wheel beingrotated so thatits operated surface moves past, and in the same direction as, theportion of the work surface being ground by. said grinding wheel, andthe third of which means includes a member for holding work of roundsection in operative relation to said two wheels; means for moving oneof said means to change the relation of the grinding throat to the workand to condition the grinding throat to receive a work-piece; and meansacting in timed relation to the actuation of said last-mentioned meansfor effecting movement of a work-piece into the grinding throat.

27. In apparatus of the character described,

in combination, a grinding throat adapted for simultaneous grinding androtating action upon work of round section and comprising three means,one of which means is in the form of a'grinding wheel adapted to berotated'at a relatively high speed, another of said means being in theform of a regulating wheel adapted to be rotated at a relatively lowspeed to control the rotation of the work, the portion of the worksurface contacted by the regulating wheel moving in the same d1-:rection as the operativesurface of the regulating wheel and thegrinding wheel being rotated'so that its operative surface moves past,and in the same direction as, the portion of the work surface beingground by said grinding wheel, and the third of which means includes amember for holding work of round section in operative relation to saidtwo wheels; power-driven means for moving one of the said means tochange the relation of the grinding throat to the work and therebytoeflect a release of the work from the grip of the wheels and meanscontrolled by sai said means being in the form of a regulating wheeladapted to be rotated atv a relatively low speed to control therotationof the work, the portion of thework surface contacted by the regulatingwheel movin in the same direction as the operative surface of theregulating wheel and the grinding wheel being rotated so that itsoperative surface moves past, and in the same direction as, the portionof the work surface being ground by said grinding wheel, and the thirdof which means includes a member for holding work of round section inoperative relation to said two wheels; means for moving one of saidmeans to change the relation of the grindingthroat to the work and tocondition the grinding throat to receive a work-piece; a magazine forholding a supply of work-pieces; and means operating in timed relationto the actuation of said last-mentioned means for transferring a.work-piece frofii said magazine into said grinding throat.

29. In apparatus of the character described, in combination, a grindingthroat adapted for simultaneous grinding and rotating action upon workof round section and comprising three means, one of which means is inthe form of a grinding wheel adapted to be rotated at a relatively highspeed, another of said means being in the form of a regulating wheeladapted to be rotated at a 'relatively low speed to control the rotationof the work, the portion of the work surface contacted by the regulatingwheelmoving in the same direction as the, operative surface of theregulating wheel and the grinding wheel being rotated so that itsoperative-surface. moves past, and in the same direction as,

the portion of the work surface being-ground by said grinding wheel, andthe third of which means includes a member for holding work of round 7section in operative relation to said two wheels; mechanism operating inrecurring sequence to change the relation of one of said means withrespect to another, thereby to eifect a release of a work-piece from thegrip of the' wheels; and means acting in timed relation with respect tosaid mechanism for effecting a movement of the work out of said grindingthroat.

30. In apparatus of the character described, in combination, a grindingthroat adapted for simultanenous grinding and rotating action upon workof round section and comprising three means, one of which means is inthe form of a grinding wheel adapted to be rotated at a relatively highspeed, another of said means being in the form of a regulating wheeladapted to be rotated at a relatively low speed to control the rotationofthe work, the portion of the work surface contacted by the regulatingwheel moving in the same direction as the operative surface of theregulating Wheel and the grinding wheel beingrotated so that itsoperative surface moves past, and in the same direction as, the portionof the work surface being ground by said grinding wheel, and the thirdof which means includes a member for holding work of round section inoperative relation to said two wheels; means adapted upon operation tochange the relation of one of said means with respect to another andthereby condition said grinding throat for the in sertion of awork-piece; a magazine adapted to hold a supply of work-pieces; guidingmeans for guiding a work-piece from said magazine into said grindingthroat, and means acting in timed relation with respect to saidgrinding-throat-conditioning means for effecting a movement ofawvork-piece from said magazine and along said guiding means.

81. In apparatus of the character described, in combination, a grindingthroat adapted for simultaneous grinding and rotating action upon workof roundsection and comprising three means, one of which means is in theform of a grinding wheel adapted to be rotated at a relatively highspeed, another of said means being in the form of a regulating wheeladapted to be rotated at a relatively low speed to control the rotationof the work, the portion of the work surface contacted by the regulatingwheel moving in the same direction as the operative surface of theregulating wheel and the grinding wheel being rotated so that itsoperative surface moves past, and in the same direction as, the portionof the work surface being ground by said grinding wheel, and the thirdof which means includes a-member for holding work of round sectionin oerative relation to said two wheels; means at apted upon operationthereof to change the relation of one of said means with respect toanother and there-'. by condition said grinding throat for the removalof awork-plece therefrom; and means for preventing contact with thegrinding wheel of a work-piece being removed from the grinding throat. g

32. In apparatus of the character described, in combination, a grindingthroat adapted for simultanenousgrinding and ro tating action upon workof round section and comprising three means, one of which means is inthe form of a grinding wheel adapted to be rotated at a relatively highspeed, another of said means being in the form of a regulating wheeladapted to be rotated at a relatively low speed to control the rotationof the work, the ortion of the work surface contacted by tl i eregulating Wheel moving inthe same direction as the o erative surface ofthe regulating Wheel and t e grinding wheel being rotated so that itsoperative surface moves past, and in the same direction as, the portionof the work surface being ground by said grinding wheel, and the thirdof which means includes a member for holding work of round section inoperative relation to said two wheels; means adapted upon operationthereof to change the relation of one of said means to another andthereby condition said grinding throat for the insertion of awork-piece; and means for preventing contact with the grinding wheel ofa work-piece being inserted into said grinding throat.

33. In apparatus of the character described, in combination, a grindingthroat adapted for simultanenousgrinding and rotating action upon Workof round section and comprising three means, one of which means is inthe form of a grinding wheel adapted to be rotated at a relatively highspeed, another of said means being in the form of a regulating wheeladapted to be rotated at a relatively low speed to control the rotationof the work, the portion of the work surface contacted by the regulatingwheel" moving in the same direction as the operative surface of theregulating wheel and the grinding wheel being rotated so that itsoperative surface moves past, and in the same direction as, the portionof the work surface beingground by said grinding wheel, and the third ofwhich means includes a member for holding work of round section inoperative relation to said twowheels; the operative surface of saidregulating wheel having a path of travel substantially at rig tact withthe Wor whereby feeding movement of work in an axial direction isprevented; and means for effectin a movement of a work-piece into saidgrindlng throat for rotation bythe regulating wheel and for grindingaction thereon by the grinding wheel and for effecting a movement ofsaid work-piece out of said grinding throat. 34. In apparatus of thecharacter described, 'in combination, a grinding throat adapted 4 orsimultaneous tion upon work 0 round section and comprising three means,one of which means is in the form of a grinding wheel adapted to be tangles to its line of conrinding and rotating acf rotated at arelatively high speed, another of said means being ii, I 'Ir orm of aregulating wheel adapted to be rotated at a relatively low speed tocontrol the rotation of the work, the portion of the work surfacecontacted by the regulating wheel moving in the same direction as theoperative surface of the regu lating Wheel and the grinding wheel beingrotated so that its-operative surface moves past, and in the samedirect-ion as, the ortion of the work surface being ground y saidgrinding wheel, and the third of which means includes a member forholding work of round section in operative relation .to said two wheels;the operative surface of said regulating wheel having a path of travelsubstantially at rightangles to its line of contact with'the work,whereby said regulating wheel of a grinding wheel adapted to be rotatedat a relatively high speed, another of said means being in the form of aregulating wheel adapted to be rotated at a relatively low speed tocontrol the rotation of the work, the portion of the work surfacecontacted by the regulating wheel movin in the same direction as theoperative sur ace of the regulating wheel and the grinding wheel beingrotated so that its operative surface moves past, and in the samedirection as, the portion of the work surface being ground by saidgrinding wheel, and the third of which means includes a member forholding work of round section in operative relation to said two wheels;the operative surface ofsaid regulating wheel having a path of travelsubstantially' at right angles to its line of contact with the work;whereby said regulating wheel controls the rotation of the work-piecewithout feeding movement thereof in an axial direction; and meansforeifecting a removal of a work-piece from said grindin throat.

36. In apparatus of the character described, in combination, a grindingthroat adapted for simultaneous grinding and rotating action upon workof round section and comprlsing three means, one of'which means is inthe form of a grinding wheel adapted to be rotated at a relatively highspeed, another of said means being in the form of a regulating wheeladapted to be rotated. at a relatively low speed to control the rotationof the work, the portion of the work surface contacted by the regulatingwheel moving in the same direction as the operative surface of theregulating wheel and the grinding wheel being rotated so that-itsoperative surface moves grinding-throat-conditioning means.

past, and in the same direction as, the portion of the work surfacebeing ground by said grinding wheel, and the third of which meansincludes a member for holding work of round section in operativerelation to said two wheels; the operative surface of said regulatingwheel having a path of travel substantially atright angles to its lineof contact with the work, whereby said regulating wheel controls therotation of the work-piece without feeding movement thereof in an axialdirection; and means under the control of a poweractuated member foreffecting a removal of "the work-piece from said grinding throat.

37. In apparatus of the character described, in combination, agrindingthroat adapted for simultaneous grinding and rotating -actionupon work of round section and comprising three means, one of whichmeans is in the form of a grinding wheel adapted to be ro-' tated at arelatively high speed, another of said means being in the form of aregulating wheel adapted to be rotated at a relatively low speed tocontrol the rotation of the work,

the portion of the work surface contacted by the regulating wheel movingin the same direction as the operative surface of the regulating wheeland the grinding wheel being rotated so thatitsoperative surface movespast, and in the same direction as, the portion of the Work surfacebeing ground by said grinding wheel and the third of which meansincludes a member for holding work of round section in operativerelation to said two wheels; means adapted upon operation .to

change the relation ofone of said means with respect to the other and tothereby condition said grinding throat for the insertiontherein of awork-piece; -a magazine for holding a open1ng;.a reciprocating memberadapted in supply of work-pieces a'nd provided with an one position toclose said'opening'to prevent egress of a work-piece from said magazine,said reciprocating member being adapted upon operation to permit releaseof a workpiece from the magazine and to effect a move- B16111), of awork-piece into said grinding" throat; and means for operating saidreciprocatlng member 1n. timed relation to said 38. In apparatus of thecharacter described, I

. the portion of the worksurface contacted by the regulating wheelmoving in the same direction as the operative surface of the regulatingwheel and the grinding wheel being rotated so that its operative surfacemoves said grindin wheel, and the third of which means inclu es'amemberfor holding work of round section in operative relation to saidtwo wheels; said grinding throat presenting at least three lines ofcontact to work of round section inserted therein; means for guiding awork-piece into said grinding throat; and a plunger foreffecting'movement of a work-piece along said guiding means and therebyeifect its introduction into I said grinding throat.

39. In apparatus of the character described, in combination, a grindingthroat adapted for simultaneous grinding and rotating action upon workof round section and comprising three means, one of which means is inthe form of a grinding wheel adapted to be rotated at a'relatively highspeed,flanother of said means being in the form of a regulatingwheeladapted to be rotated at a relatively low speed to control therotation of the work, the portion of the work surface contacted by theregulating wheel moving in the same direction as the operative surfaceof the. regulating wheel and the grinding wheel be-,

ing rotated so that its operative surface moves past,and in the samedirection as, the por-' tion of the work surface being ground by saidgrinding wheel, and the third of which means includes a' member forholding work of round section in operative relation to said twowheelspsaid grinding throat presenting at least three lines ofcontact towork of round section inserted therein; means for guiding a work-pieceinto said grindmg throat; a member mounted for reciprocation and adaptedupon operation in one direction to permit positioning of a workpiece inadvance thereof and upon operation in its other direction to effectmovement of said work-piece along said guiding means and thereby toeffect its introduction into said grinding throat.

40. In apparatus of the character de-' scribed, in combination, agrinding wheel adapted to be rotated at relatively high speed, aregulating wheel adapted to be rotated at relatively low speed, saidwheels being adapt ed to presentadj acent operative surfaces travclingin opposite directions, means for guiding a work-piece of roundsectioninto operative relation to said two wheels, a magazine forholding a supply of work-pieces and operatively related to said guidingmeans. and intermittently operative means adapted to provide an openingthrough which an individual work-piece may be passed from said magazineinto operative relation to said guiding means.

41. In apparatus of the character described, in combination, a grindingthroat adapted for simultaneous" grinding and rotating action upon workof round section and comprising three means, one of which means is inthe form of a grinding wheel adapted to tively low speed to control therotation. of the Work, the ortion of the work surface contacted by t 1eregulating wheel moving in the same direction as the operative surfaceof the regulating wheel and the grinding wheel being rotated so that itsoperatives'urface moves past, and in the same direction as, the portionof the work surface being ground by said grinding wheel, and the thirdof which means includes a member for holding work of round section inoperative relation to said two wheels; means for changing the relationof one of said means with respect to another and to thereby conditionsaid grinding throat to receive a work-piece; andmeans operating intimed relation with respect to said last-mentioned means for effecting amovement of a work piece into said grinding throat and in a directionsubstantially transverse to the direction in which said grinding throatextends.

42. In apparatus of the character described, in combination, a grindingthroat adapted for simultanenous grinding and rotating action upon workof round section and comprising three means, one of which means is inthe form ofa grinding wheel adapted to be rotated at (a relatively highspeed, another of said means being in the form of a regulating wheeladapted to be rotated at a relatively low speed to control the rotationof the work, the portion of the work surface contacted by the regulatingwheel moving in the same direction as the operative surface of theregulating wheel and the grinding wheel be ing rotated so that itsoperative surface moves past, and in the same direction as, the portionof the work surface being ground by said grinding wheel, and the thirdof which means includes a member for holding work of round section inoperative relation to said two wheels; means for changing the relationof one of said means relative to another and section in operativerelation to said two wheels; a main driving shaft rotatably sup-' portedby said frame and adapted to be connected to a source of power; drivingCOIIIIGC- tions between said shaft and said wheels having includedtherein speed-change mechanism arranged to permit said grinding wheel tobe driven at-a relatively high speed and saidranged to efiect areciprocating movement of said grinding wheel lengthwise of the workoperated upon thereby.

44. In apparatus of the general nature of that herein described, incombination, a main frame; a grinding wheel supported thereby; aregulating wheel supported by saidframe and operatively related to saidgrinding wheel means for holding work of round section in operativerelation to said two wheels; a main driving shaft rotatably supported bysaid frame and adapted to be connected to a source of power; drivingconnections between said shaft and said wheels having ineluded thereinspeed-change mechanism arranged to permit said grinding wheel to bedriven at a relatively high speed to grind the work and said regulatingWheel at a relatively low speed to control the rotation of the work,

'the portion of the work surface contacted bythe regulating wheel movingin the same direction as the operative surface of the regulating wheeland the grinding wheel being rotated so that-its operative surfacemovespast,

and in the same direction as, the portion of the work surface beingground by said grinding wheel; and operative connections includingspeed-change mechanism for effecting a reciprocating movement of saidgrinding wheel in a directlon substantially lengthwise of the workoperated upon thereby.

45.. In apparatus of the-generalnature that herein-described, incombination, a main;

of the work surface being ground by said grinding wheel; a membermounted for re-' ciprocation and adapted upon reciprocatin by; and meansincluding speed-reducing gearing driven from said main driving shaft forreciprocating said member. s

46. In apparatus of the general nature of that herein described, incombination, a main frame; a grinding throat adapted for simultaneousgrinding and rotating action on work of round section and comprisingthree means, supported by said main frame, one of' which means is in theform of a grinding wheel, another of said means being in the form of aregulating wheel, and the third of which means includes a member forholding Work of round section in operative relation to said two wheels;a main driving shaft rotatably supported by said frame and adapted to beconnected to a source of power; driving connections between said shaftand said wheels having included therein speed-change mechanism arrangedto permit said regulating wheel to be driven at a relatively low speedto control the rotation of the work, the portion of the work surfacecontacted by the regulating wheel moving in the same di rection as theoperative surface of the regulat- ,ing wheel and the grinding wheelbeing ro-' tated so that its operative surface moves past, 1

and in the same direction as, theportion of the work surface beingground by said grind ing wheel; and mechanism driven from said maindriving shaft for periodically changing the relation between said meansforming said grinding throat.

47. In apparatus of the general nature ofthat herein described, incombination, a main frame; a grinding throat adapted for simul-- taneousgrinding and rotating action on work of round section and comprisingthree means, supported by said main frame, one of which frame; agrinding wheel supported thereby; means is in the form of a grindingwheel, an-

relatively-high speed to grind the work and,

said regulating wheel at a relatively low s eed to control the rotationof the work, t e portion of the work surface contacted by the regulatingwheel moving in the same direction as the operative'surface of theregulating wheel and the grinding wheel being rotated so that itsoperative surface moves past. and in the same direction as, the pprtionother of said means beingin the form of a regulating wheel, and thethird of which means, includes a member for holding work.

'of round section in operative relation to said two wheels; 2. maindriving shaft rotatably supported by said frame and adapted to beconnected to a source of power; driving connections between saidshaftand said wheels having included therein speed-change mechanism arrangedto permit said regulating wheel to be driven at a relatively low speedto control the rotation of the work, the portion ofthe work surfacecontacted by the regulat-j ing wheel moving in the same direction as theoperative surface of the regulating Wheel and the grinding wheel beingrotated so that its int operative surface moves past, and in the samedirection as, the portion of the work surface being ground by saidgrinding wheel; mechanismdriven from said main driving shaft forperiodically changing the relation between said means forming saidgrinding throat; and mechanism driven from said main driving shaft foreffecting a relative reciprocating movement in a direction lengthwise ofthe work between the grinding wheel and the work.

48. In apparatus of the general nature of that herein described, incombination, a main frame; a grinding throat adapted for simul means isIm the form of a grinding wheel,

regulating wheel, and the third of .Which meansincludes a member forholding work of round section in operative relation to said two wheels;a main driving shaft rotatably supported by said frame and adapted to benections between said shaft and said wheels having included thereinspeed-change mechanism arranged to permit said regulating wheel to bedriven at a relatively low speed to control the rotation of the work,the portion. of the work" surface contacted by the regulating wheelmoving, in the same direction as the operative surface of the'regulatingwheeland the grinding wheel being rotated so that its operative surfacemoves past, and in the same direction as, the portion of the worksurface being ground by said grinding wheel; means operated from saidmain driving shaft for effecting periodically a change in the relationbetween said means forming the grinding throat and to therebyperiodically condition the latter for receiving a work-piece; and meansoperating in timed relation with respect to said last-mentioned meansfor effecting a movement of a workpiece into the grinding throat. L

49.111 apparatus of the general nature of that herein described,incombination, a main frame; a grinding throat adapted for simultaneousgrinding and rotating action on work of round section and comprisingthree means,

supported by said main frame. one of which means is in the form of agrinding wheel, another of said means being in the form of a regulatingwheel, and the third of which means includes a member for holding Workof round section in operative relation to said two wheels; a maindriving shaft rotatably supported by said frame and adapted to beconnected to a source of power; driving connections between said shaftand said wheels having included therein speed-change mechanism arrangedto permit said regulating wheel to be'driven at a relatively low speedto control the rotation of the work, the portion of the work surfacecontacted by the regulating wheel moving in the same direction as theoperative surface of the regulating t'aneous grinding and rotatingaction on work of round section and comprising three means, supportedbysaid main frame, one of wh1ch 1 another of said means being in the formof a connected to a source of power; driving con-' wheel and thegrinding wheel being rotated so that its operative surface moves past,and, in the same direction as, the portion of the .work surface beingground by said grind-.

ing wheel; means operated from said main driving shaft for efiecting aperiodic change in the relation between said means forming said grindingthroat and to thereby periodically condition the latter to release awork piece from the grip of said wheels; and means actuated in timedrelation with respect to said last-mentioned-means for effecting aremoval of a work-piece from said grinding throat.

' 50. A centerless grinding machine, "comprisin a grinding wheel; agoverning or control-w ieel peripherally opposed to the grinding wheel;a work-rest or support intermediate said wheels, said wheels havingtheir axes parallel means for rotating the grinding and governing wheelsabout their respective axes in one and the same direction, the grindingwheel at a relatively high speed and the governing wheel at a relativelylow speed; means for varying the distance between the proximateperipheral faces of said wheels;

and means for automatically removing the work from the'work-rest betweensaid wheels when the grinding is completed.

51. A centerless grinding machine comprising, in combination, a grindingwheel; a governing or control-wheel; anintermediate work-rest orsupport; means for progressively advancing and receding one of saidwheels toward and from the other; and means for automatically removingthe work from between said wheels after it is completely ground.

52. A centerless grinding machine, comprising a grinding wheel and agoverningor control-wheel peripherally opposed, saidwheels having theiraxes in common plane; means for rotating said wheels abouttheirrespective axes in one and the same direction, the grinding wheel atrelatively high speed and the governing wheel at relatively low speed;a; work-rest between the effective operating faces of said wheels, uponwhich rest the work lies without axial movement during the grinding;means for varying the distance between the opposed working faces ofthe'wheels; and means for automatically scribed, in combination, agrinding wheel adapted to be rotated at a relatively high 15 speed, aregulating wheel adapted to be rotated at a relatively low speed, saidwheels being adapted to present adjacent operative surfaces travelin inopposite directions, means extendin between said wheels for holding work0 round section in operative relation to said wheels, andpower-controlled means for bringing about a movement of the work in adirection substantially transverse to its axis and into or out ofoperative relation with respect to said adjacent operative surfaces ofsaid two wheels.

55. ,In apparatus of the character described, in combination, a grindingwheel adapted to be rotated at'a relatively high speed, a regulatingwheel adapted to be rotated at a relatively low speed, said wheels beingadapted to present adjacent operative surfaces traveling in pppositedirections, means extending between said wheels for holding work ofround section in operative relation to said wheels, said regulatingwheel being positioned on one side of said work-holdingmeans and adaptedto control the rotation of the work and said'grinding wheel beingpositioned 'on the other side of said work-holding means and movable inthe general direction in whlch said holding means extend, and means forreciprocating said movable grinding wheel comprising a rotatablecrank,'connect1ons between said crank and said grinding wheel, and'means for varying the throw of said crank. v

56. In apparatus of the character descrlbed, in combination, 'a grindingthroat adapted for simultaneous grinding and rotating action upon workof round section and comprising three means, one of which means is inthe form of a grinding wheel adapted to be rotated at a relatively highspeed, another of said means being in the form of a regulating wheeladapted to be rotated at a relatively low speed to control the rotationof the work, the portion of the work surface contacted by the regulatingwheel moving in the same direction as the operative surface of theregulating wheel and the grinding wheel being retated so that itsoperative surface moves past, and in the same direction as, the portionof the work surface being ground by sald grinding wheel, and the thirdof which means meludes amember for holding work of round section inoperative relation to said two prising three means, one of which meansis,

in the form of a grinding wheel adapted to be rotatedat a relativelyhigh speed, an other of said means being in the form of a regulatingwheel adapted to be rotated ata relatively low speed to control therotation of the work, the portion of the work surface contacted by theregulating wheel moving in the same direction as the operative surfaceof the regulating wheel and the grinding wheel being rotated so that itsoperative surface moves past, and in the same direction as, the portionof the work surface being ground by said grinding wheel, and the thirdof which means includes a member for, holding work OfIOUIlCl section inoperative-relation to said two wheels; a driven shaft; means operatedfrom said driven shaftffor moving one of said means to change therelation of the grinding throat to the work; and clutch for controllingthe operation of said last-mentioned means from said driven shaft.

58. In apparatus of the general nature of that herein described, incombination, a main frame; a grinding throat adapted for simultaneousgrinding and rotating action on work of round section and comprisingthree means,

supported by said main frame, one of which means is in the form of agrinding wheel, another of said means being in the form of a regulatingwheel, and the third of which means includes a member for holding workof round section in operative relation to said two wheels; a maindriving shaft rotatably supported by said frame-and adapted to beconnected to a source of power; driving connections between'said shaftand said wheels having included therein speed-change mechanism arrangedto permit said grinding Wheel to be driven at relatively high speed togrind the work and. said regulating wheel at'a relatively low speed tocontrol the rotation of the .work, the portion of the work surfacecontacted by the regulating wheel moving in the same direction as theoperative surface of the regulating wheel and the grinding wheel beingrotated so that its operative surface moves past, and in the samedirection as, the portion of the'work surface being ground by saidgrindin wheel; means oper-- ated from said main riving shaft foreffecting periodically a change in the relation

